View Full Version : Carbon fiber blockers now exist.

Mike Puckett
08-21-2007, 07:39 PM
I went over to pick up a couple of bearings for my spare M5R2 for my drag racer and while I was talking to the salesman another one came over and plunked a box of carbon fiber blockers in front of me. They have stock number SRK248B on the box. There are 4 large fiber blockers and 2 small brass ones for 5th and reverse. They had 3 boxes at $200 each and I bought 2 of them which means I'll be staying with the 5spd for awhile. I don't know who makes them but if you're interested call Southern Gear 770-435-1461 and see if the other set is still there or ask them to order more of them. They are a little different as can be seen in the photos but they fit and work in the transmission on the bench, gripping and holding the gear firmly as the synchro slider engages it. The little fiber pucks are smaller but there are twice as many of them. A couple of the rings in the 2 sets had little chips out of a couple of the pucks indicating that shear resistance may not be optimal but with fluid I hoping it won't be an issue. I measured the electrical resistance and measured about 100 ohms/inch and 40 ohms to the brass ring. It'll be awhile before I put them to the test and see how they hold up but they are myth no more.
BTW, I called drivetrain.com and they have limited numbers of OEM fiber blockers at any given time for $331 per set.

Duffy Floyd
08-21-2007, 07:42 PM
How come there are not as many teeth on the carbon fiber blockers as the OEM version???? See any potential effect there Mike??????

Mike Puckett
08-21-2007, 08:18 PM
I've had a Tremec tech rep and one of the techs from Southern Gear both tell me to cut off every other tooth on the blocker to make it shift quicker and resist crunching better especially with the solid brass blockers. It's not quite the same thing but I don't see a problem here. There's 3 teeth per gap and there's plenty of other teeth for the slider to catch and lock onto. On the bench the slider captures the blocker the same as the others.

XR7 Dave
08-21-2007, 08:58 PM
Those are the same "fiber" blockers that I got from Southern gear about a year ago for Doug Walker's transmission. I wasn't aware that they were carbon fiber, I just assumed it was some aftermarket fiber. Weird. I think I paid about $45 each for them. I guess someone could ask him what he thought of them.

08-22-2007, 03:29 PM
The other box is officially MINE!


Night Wing
03-14-2009, 05:51 PM
so whats everyones opinions on these?


03-15-2009, 12:36 PM
thats $200 for 1-5 plus R

03-15-2009, 12:59 PM
~$300 shipped from Southern Gear

1st-4th gear blocker rings - carbon fiber
Reverse gear blocker rings - brass
5th gear blocker rings - brass
main shaft nut
counter shaft nut
front and rear seals

Mike Puckett
03-15-2009, 04:32 PM
So far the carbon fiber blocker is doing OK. I only have one in 3rd gear. Occasionally I get a crunch shifting to 3rd if I hurry it, but at full power on a speed shift it shifts good without a crunch. The OEM ones do shift a little better, though.